The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.
Known powertrain architectures include torque-generative devices, including internal combustion engines and torque machines that transfer torque through a transmission device to an output member. One exemplary powertrain includes a multi-mode hybrid transmission having an input member that receives tractive torque from a prime mover power source and torque machines and transfers torque to an output member. The output member can be operatively connected to a driveline for a motor vehicle for transferring tractive torque thereto. The torque machines can include electric machines that operate as motors or generators and generate torque inputs to the transmission independently of a torque input from the internal combustion engine. The torque machines may transform vehicle kinetic energy transferred through the vehicle driveline to potential energy that is storable in an energy storage device through a process referred to as regenerative braking. A control system monitors various inputs from the vehicle and the operator and provides operational control of the powertrain, including controlling transmission operating state and gear shifting, controlling the torque-generative devices, and regulating the power interchange among the energy storage device and the torque machines to manage outputs of the transmission, including torque and rotational speed. Known multi-mode hybrid transmissions can use differential gearing, torque transfer clutches, and the torque machines to transfer power to an output member that can be connected to a driveline when the powertrain is applied to a vehicle.
Known transmission devices have spin losses that affect energy efficiency of the transmission and thus affect fuel economy. Transmission spin losses can be caused by friction between contiguous non-applied friction clutch plates.
Selectable one-way clutch devices (SOWCs) can be used in some transmissions to reduce spin losses. Known selectable one-way clutch devices (SOWCs) can transfer torque between contiguous coaxial rotating devices when applied. Each of the contiguous rotating devices has a race. One race is oriented radially concentric to and opposing the race of the other rotating device, or the two races are opposite each other axially. A multiplicity of controllable torque transferring devices, e.g., rollers, sprags, rockers or struts, are connected to one of the races and positioned to oppose the other race. The opposed race includes a multiplicity of surface receiving features corresponding to the controllable torque transferring devices. Known selectable one-way clutch devices are applied by controlling the controllable torque transferring devices to interact with and connect to the surface receiving features to lock rotations of the contiguous rotating devices to transfer torque therebetween. Known selectable one-way clutch devices can lock rotations of the contiguous rotating devices when rotating in a first direction. Thus, when one of the contiguous rotating devices rotates in the first direction, torque is transferred to the other contiguous rotating device. When the contiguous rotating device rotates in a second direction opposite to the first direction, no torque is transferred, permitting the rotating device to freewheel. In one embodiment, a selectable one-way clutch device can include controllable torque transferring devices that can be controlled to a first position to interact with and connect to the surface receiving features to lock rotations of the contiguous rotating devices when rotating in one direction, and can also be controlled to a second position to interact with and connect to the surface receiving features to lock rotations of the contiguous rotating devices when rotating in the second direction opposite to the first direction. Known selectable one-way clutch devices can be controlled to another position to interact with and connect to the surface receiving features to lock rotations of the contiguous rotating devices when rotating in both the first direction and the second direction. Known selectable one-way clutch devices can be controlled to another position to unlock rotation of the contiguous rotating devices when rotating in both the first direction and the second direction. Known selectable one-way clutch devices require substantially synchronous rotation of the contiguous rotating devices prior to applying the controllable torque transferring devices.